A wave of Kurdish rebel attacks targeting police and soldiers in south-east Turkey have killed at least 12 people.

Turkish officials said rebels of the Kurdistan Workers' Party, or PKK, launched simultaneous bomb attacks targeting police vehicles in the city of Diyarbakir and the town of Kiziltepe, killing eight people, while four soldiers were killed in a separate attack near the border with Iraq hours earlier.

The attack in Kiziltepe was caused by a roadside bomb that went off as a police bus was passing by. Three people were killed and at least 25 others were injured, including at least five young children.

At the same time, a car bomb explosion targeting police in a historic part of the city Diyarbakir killed at least five civilians and injured 12 others. The explosion occurred at a security checkpoint at a bridge over the Tigris river.

The bombings came hours after an earlier attack, also blamed on the PKK, killed four soldiers and injured nine others near the border with Iraq. The private Dogan news agency said that attack targeted military vehicles and was carried out with improvised explosives as well as rockets fired from northern Iraq.

Clashes between the PKK and Turkey's security forces resumed last year after a tenuous ceasefire collapsed, and the PKK has frequently targeted police or military with roadside explosives or car bombs.

The latest attacks came as Turkey is still reeling from a violent coup attempt on July 15 that killed at least 270 people.

The government has blamed the failed coup on the supporters of US.-based Muslim cleric Fethullah Gulen and has embarked on a sweeping crackdown on his followers.

The country is also combating the Islamic State group, whose militants have carried out a series of bloody attacks in Turkey in the past year.

Since hostilities with the PKK resumed last summer, more than 600 Turkish security personnel and thousands of PKK militants have been killed, according to the state-run Anadolu Agency. Human rights groups say hundreds of civilians have also died.